Vesicular Stomatitis Virus-Based Ebola Vaccine Is Well-Tolerated and Protects Immunocompromised Nonhuman Primates

Ebola virus (EBOV) is a significant human pathogen that presents a public health concern as an emerging/re-emerging virus and as a potential biological weapon. Substantial progress has been made over the last decade in developing candidate preventive vaccines that can protect nonhuman primates against EBOV. Among these prospects, a vaccine based on recombinant vesicular stomatitis virus (VSV) is particularly robust, as it can also confer protection when administered as a postexposure treatment. A concern that has been raised regarding the replication-competent VSV vectors that express EBOV glycoproteins is how these vectors would be tolerated by individuals with altered or compromised immune systems such as patients infected with HIV. This is especially important as all EBOV outbreaks to date have occurred in areas of Central and Western Africa with high HIV incidence rates in the population. In order to address this concern, we evaluated the safety of the recombinant VSV vector expressing the Zaire ebolavirus glycoprotein (VSVΔG/ZEBOVGP) in six rhesus macaques infected with simian-human immunodeficiency virus (SHIV). All six animals showed no evidence of illness associated with the VSVΔG/ZEBOVGP vaccine, suggesting that this vaccine may be safe in immunocompromised populations. While one goal of the study was to evaluate the safety of the candidate vaccine platform, it was also of interest to determine if altered immune status would affect vaccine efficacy. The vaccine protected 4 of 6 SHIV-infected macaques from death following ZEBOV challenge. Evaluation of CD4+ T cells in all animals showed that the animals that succumbed to lethal ZEBOV challenge had the lowest CD4+ counts, suggesting that CD4+ T cells may play a role in mediating protection against ZEBOV

Autoimmunity and frontotemporal dementia

Background: Frontotemporal Dementia (FTD) is a neurodegenerative disorder which asymmetrically affects the frontotemporal lobe, characterized by behavioural abnormalities, language impairment, and deficits of executive functions. Genetic studies identified mutations causing the disease, namely Microtubule Associated Protein Tau (MAPT), Granulin (GRN) and chromosome 9 open reading frame 72 (C9orf72) mutations, which contributed to elucidate the molecular pathways involved in brain depositions of either Tau or TAR DNA-binding protein 43 (TDP43) inclusions. However, in the majority of sporadic FTD patients, the mechanisms triggering Tau or TDP43 protein deposition are still to be uncovered. Objective: We aimed to present an extensive evaluation of literature data on immune homeostasis in FTD, in order to provide potentially evidence-based approaches for a disease still orphan of any treatment. Methods: A structured search of bibliographic databases from peer-reviewed literature was pursued focusing on autoimmunity in the brain and FTD. Results: One-hundred-fourteen papers were included in this review. The majority of studies (32) were represented by extensive literature revision on immunity, central nervous system (CNS) and autoimmunity; neuroimaging papers (11) in autoimmune diseases were evaluated, and immunomodulatory approaches (25) were revised. Six papers were found specifically related to FTD and autoimmune hypothesis, the other papers referring to current state of art on FTD. Conclusion: Overall this review contribute to expand the knowledge of a possible immune hypothesis in FTD, suggesting therapeutic perspectives in autoimmune related neurodegeneration, to reduce or revert the disease

Predictors of “brain fog” 1 year after COVID-19 disease

Introduction: Brain fog has been described up to 1 year after SARS-CoV-2 infection, notwithstanding the underlying mechanisms are still poorly investigated. In this study, we aimed to evaluate the prevalence of cognitive complaints at 1-year follow-up and to identify the factors related to persistent brain fog in COVID-19 patients. Methods: Out of 246 COVID patients, hospitalized from March 1st to May 31st, a sample of 137 patients accepted to be evaluated at 1 year from discharge, through a full clinical, neurological, and psychological examination, including the Montreal Cognitive Assessment (MoCA), impact of event scale-revised (IES-R), Zung self-rating depression scale (SDS), Zung self-rating anxiety scale (SAS), and fatigue severity scale (FSS). Subjects with prior cognitive impairment and/or psychiatric disorders were excluded. Results: Patients with cognitive disorders exhibited lower MoCA score (22.9 ± 4.3 vs. 26.3 ± 3.1, p = 0.002) and higher IES-R score (33.7 ± 18.5 vs. 26.4 ± 16.3, p = 0.050), SDS score (40.9 ± 6.5 vs. 35.5 ± 8.6, p = 0.004), and fatigue severity scale score (33.6 ± 16.1 vs. 23.7 ± 12.5, p = 0.001), compared to patients without cognitive complaints. Logistic regression showed a significant correlation between brain fog and the self-rating depression scale values (p = 0.020), adjusted for age (p = 0.445), sex (p = 0.178), premorbid Cumulative Illness Rating Scale (CIRS) (p = 0.288), COVID-19 severity (BCRSS) (p = 0.964), education level (p = 0.784) and MoCA score (p = 0.909). Conclusions: Our study showed depression as the strongest predictor of persistent brain fog, adjusting for demographic and clinical variables. Wider longitudinal studies are warranted to better explain cognitive difficulties after COVID-19

Progression of behavioural disturbances in frontotemporal dementia: a longitudinal observational study

Background and purpose: Behavioural disturbances are the core features of frontotemporal dementia (FTD); however, symptom progression is still not well characterized during the entire course of the disease. The aim of the present study was to investigate behavioural symptoms at baseline and during the disease course in a large cohort of patients with behavioural variant FTD (bvFTD), non-fluent/agrammatic variant primary progressive aphasia (nfvPPA) and semantic variant primary progressive aphasia (PPA). Methods: We evaluated 403 patients with FTD, 167 of whom had at least 1-year follow-up evaluation (for a total of 764 assessments). Behavioural symptoms were assessed and rated through the Neuropsychiatric Inventory (NPI) and Frontal Behavioural Inventory (FBI). Disease severity was evaluated through the Frontotemporal Lobar Degeneration -Clinical Dementia Rating scale (FTLD-CDR). Linear mixed models were used to model behavioural measures (NPI, FBI and the five FBI-behavioural core criteria scores) as a function of disease severity (FTLD-CDR score) and clinical phenotype. Results: At baseline, patients with bvFTD showed more behavioural disturbances compared with those with nfvPPA (P = 0.004). Negative symptoms (apathy and loss of empathy) showed a trend to an increase throughout the course of the disease in both bvFTD and PPA (P < 0.001 until intermediate stages). Positive symptoms (disinhibition, perseverations and hyperorality) increased until intermediate phases (P < 0.001) followed by a progressive reduction in later phases, whereas they were less common in nfvPPA throughout the disease course. Conclusion: We demonstrated that behavioural disturbances differed in FTD and with disease severity. Positive symptoms appeared to improve in the advanced stages, highlighting the importance of taking into account the disease severity as outcome measure in clinical trials

Brain connectivity and information-flow breakdown revealed by a minimum spanning tree-based analysis of mri data in behavioral variant frontotemporal dementia

Brain functional disruption and cognitive shortfalls as consequences of neurodegeneration are among the most investigated aspects in current clinical research. Traditionally, specific anatomical and behavioral traits have been associated with neurodegeneration, thus directly translatable in clinical terms. However, these qualitative traits, do not account for the extensive information flow breakdown within the functional brain network that deeply affect cognitive skills. Behavioural variant Frontotemporal Dementia (bvFTD) is a neurodegenerative disorder characterized by behavioral and executive functions disturbances. Deviations from the physiological cognitive functioning can be accurately inferred and modeled from functional connectivity alterations. Although the need for unbiased metrics is still an open issue in imaging studies, the graph-theory approach applied to neuroimaging techniques is becoming popular in the study of brain dysfunction. In this work, we assessed the global connectivity and topological alterations among brain regions in bvFTD patients using a minimum spanning tree (MST) based analysis of resting state functional MRI (rs-fMRI) data. Whilst several graph theoretical methods require arbitrary criteria (including the choice of network construction thresholds and weight normalization methods), MST is an unambiguous modeling solution, ensuring accuracy, robustness, and reproducibility. MST networks of 116 regions of interest (ROIs) were built on wavelet correlation matrices, extracted from 41 bvFTD patients and 39 healthy controls (HC). We observed a global fragmentation of the functional network backbone with severe disruption of information-flow highways. Frontotemporal areas were less compact, more isolated, and concentrated in less integrated structures, respect to healthy subjects. Our results reflected such complex breakdown of the frontal and temporal areas at both intra-regional and long-range connections. Our findings highlighted that MST, in conjunction with rs-fMRI data, was an effective method for quantifying and detecting functional brain network impairments, leading to characteristic bvFTD cognitive, social, and executive functions disorders

Premorbid vulnerability and disease severity impact on Long-COVID cognitive impairment

Background: Cognitive deficits have been increasingly reported as possible long-term manifestations after SARS-CoV-2 infection. Aims: In this study we aimed at evaluating the factors associated with cognitive deficits 6 months after hospitalization for Coronavirus Disease 2019 (COVID-19). Methods: One hundred and six patients, discharged from a pneumology COVID-19 unit between March 1 and May 30 2020, accepted to be evaluated at 6 months according to an extensive neurological protocol, including the Montreal Cognitive Assessment (MoCA). Results: Abnormal MoCA scores at 6 months follow-up were associated with higher pre-hospitalization National Health System (NHS) score (Duca et al. in Emerg Med Pract 22:1–2, 2020) (OR 1.27; 95% CI 1.05–1.6; p = 0.029) and more severe pulmonary disease expressed by the Brescia-COVID Respiratory Severity Scale (Duca et al. in Emerg Med Pract 22:1–2, 2020) (BCRSS > 1OR 4.73; 95% CI 1.53–14.63; p = 0.003) during the acute phase of the disease. Discussion: This longitudinal study showed that the severity of COVID-19, indicated by BCRSS, and a complex score given by age and premorbid medical conditions, expressed by NHS, play a major role in modulating the long-term cognitive consequences of COVID-19 disease. Conclusions: These findings indicate that the association of age and premorbid factors might identify people at risk for long-term neurological consequences of COVID-19 disease, thus deserving longer and proper follow-up

Expanding the role of education in frontotemporal dementia: a functional dynamic connectivity (the chronnectome) study

In the present study, we aim at investigating whether education modulates dynamical properties of time-varying whole-brain network connectivity (the chronnectome) in frontotemporal dementia (FTD) at a given level of symptom severity. Dynamic connectivity parameters were evaluated in 128 patients with FTD using independent component analysis, sliding-time window correlation, and k-means approach to resting state–magnetic resonance imaging data. We evaluated the relationship between education, a proxy measure of cognitive reserve, and 4 indexes of metastate dynamic connectivity: (1) the number of distinct metastates a patient passes through, (2) the number of switches from one metastate to another, (3) the span of the realized metastates, and (4) the total distance traveled in the state space. We found a significant inverse correlation between years of education and the 4 indexes of metastate dynamic fluidity (all p-values ≤ 0.03, false discovery rate–corrected). This study suggests that patients with FTD with higher education but comparable clinical severity show more global functional brain impairment, suggesting that patients with higher cognitive reserve can cope with more global brain fluidity reduction